The girls won't leave the coop

To follow up on yesterday's posting with the ducks...apparently I have absolutely no sense of size. I thought I had bought a duck that was twice as big as the original duck at home and was worried about the new duck hurting the old duck even though the only purpose of getting the new duck was to give the old duck a friend.  Well, they are the exact same size!  When I saw they were the same size, I happily placed them together thinking all would go well.  It did not go well.  Since old duck has been living with chickens since she was three days old, she thinks she is a chicken. She started pecking new duck mercilessly.  Poor new duck didn't know what was going on, having never been pecked by another duck before.  I told my husband what was going on, since he has more experience with fowl than I do. Husband assessed the situation and immediately began singing. That's right, he sang to the ducks because apparently that is what his fowl experience has taught him. What did he sing? Brace yourselves, it is a good one. Do you remember the song from childhood "Not a chicken Not a duck so I shake my butt..quack quack quack quack?"  If you don't know it, youtube it because it is quite catchy and funny.  Well, to that same tune my dear husband began singing "You're not a chicken you're a duck, you're not a chicken you're a duck, quack quack quack quack."  Over and over he sang this song and amazingly.....it worked!  Old duck stopped pecking new duck. They both just stared at dear husband as if he were a lunatic.  In hindsight, I now realize that his "fowl experience" mainly involves shooting and eating them but hey..it worked!
Now, my chicken woes.  Since the teenage chickens had to be kicked out of the house to make room for the new duck and new chicken we decided to put teenage chickens in their coop outside but not let them out of the coop yet. We wanted them to know that the coop was their home so they would happily march themselves into it each evening and thus prevent us from chasing chickens around the yard at night so they wouldn't be eaten by coyotes, cats, raccoons, etc.  Our strategy worked, a little too well.  The girls refuse to leave the coop.  We open it in the morning, try to gently lead them out (to our 13 year old gently means shaking the coop). I throw food in the yard, talk to them, explain to them. Nothing, those dang birds stay in that coop all day.  While I am glad that they are happy with the coop we chose for them, I want them to be free range.  I don't understand why they choose to not only stay in the coop but in the far back corner of the coop, all huddled together like they are in a prison camp.  This has been going on for a week now.  Maybe I need to get a rooster decoy to lure them out into the yard?  Or I suppose I could send dear husband out there to assess the situation and sing something to them.